Large square balers are known in the prior art. Such balers have a pickup or pickup unit for crop lying on the ground. The crop is picked up and delivered to a cutter unit, where it is reduced in size. The cutter unit enables a predetermined cut length. For this, the cutter unit has a rotor with teeth that rotates against knife edges. The knife edges can be variably set in position so as to enable no cutting or different cut lengths. The optionally cut crop is sent to a pre-compression chamber and pre-compressed into flakes. For this, the crop is caught by a stuffer and transported or lifted into a long channel that forms the pre-compression chamber. As a rule, one or two short lifts of crop made by the stuffer are pre-compressed and lifted as a flake into a rectangular bale chamber by a longer stroke. The flake is immediately captured by an oscillating rectangular plunger and pressed against a previously pre-compressed flake. In the end, a square bale forms through the successive pre-compression of several flakes.
A tying system serves to bind the individual flakes into a square bale, so that the bale density achieved as it is formed is retained and the compressed rectangular solid bale can be further processed or transported or loaded as a bale. It is disadvantageous that often, if the cut lengths are relatively short, deep cuts or pinches of the binder twine on the end faces of the square bale can be seen due to which the bale becomes misshapen and frays. This occurs when portions of the cut-short crop are not held in place, in particular between the binding twines of the square bale, and could come loose.